Gas tank sealer

This is an experiment to see how the gas tank sealer I bought wouls work out. The first thing I did was to coat a coke bottle and let it dry completely.



Then I filled it with methanol and let it sit for a week, in the course of the week, I inserted a piece of fiberglass material from a printed circuit card, this is what it looked after a week, no damage to the sealer and no damage to the fibreglass.



Then I half filled it with the nastiest gas I found so far, the one make that ruined my Fastback's tank in only one tankful, this is how it looked after another week of sitting in that swill Petro Canada calls gasoline.



Again, no damage to either the sealer, the coke bottle or the fiberglas material. It would have been nice to see something happening, but nothing, nada :?:

All I can say for sure is that neither methanol nor gasoline has any effect on this brand of gs tank sealer. It also looks like a Coke bottle would make a gas tank in a pinch :lol:

Jean

The last thing in the product information pdf says caution: "This sealer is not for use in plastic tanks"
Maybe not a good thing for long term reliability? I think i would e-mail them before doing anything.

There also seems to be this product which has an application for fiberglass and contains no MEK, haven't heard much if it tho.
http://www.kbs-coatings.com/cycle-tank- ... s-kit.html

Jean,

Nice work on your bike! A couple of years ago I stored gas in a water bottle for a week or so after using it in a pinch to drain a tank. I too noticed that the bottle was no worse for wear a week later.

As far as your experiment: It could be possible that the circuit board is manufactured with a different resin composition from the tanks - the boards are designed to go through wave soldering machines (immersion in molten lead) and I know from working with them that they are very dense and tough - not at all like the chewy resin used in tanks. I imagine the tanks were made in some cottage industry back in the '70s.
I used Caswell on my Fastback tank, and my friends Roadster - I looked into what Caswell is, epoxy phenol novolac resin. It seems to be an industrial sealant - for more info check here. broken link removed
I have no interest in Caswell - just curious as to what the sealeant was - and thinking perhaps we should buy a drum of EPNR and sell it in little cans..... :lol:
Phil

GavinJuice said:

The last thing in the product information pdf says caution: "This sealer is not for use in plastic tanks"
Maybe not a good thing for long term reliability? I think i would e-mail them before doing anything.

There also seems to be this product which has an application for fiberglass and contains no MEK, haven't heard much if it tho.
http://www.kbs-coatings.com/cycle-tank- ... s-kit.html

Click to expand...

I did call them before ordering and they said their product is OK for fiberglass tanks, they also told me their sealant was use extensively in aircraft to seal their tanks yet the data sheet that came with it said "not to be used in aircraft" I don't know if this is just a product liability warning just in case a plane crashes with this stuff in the tank but on a road vehicule, the consequences of the engine stopping are less dramatic.

Jean

fastback said:

Jean,

Nice work on your bike! A couple of years ago I stored gas in a water bottle for a week or so after using it in a pinch to drain a tank. I too noticed that the bottle was no worse for wear a week later.

As far as your experiment: It could be possible that the circuit board is manufactured with a different resin composition from the tanks - the boards are designed to go through wave soldering machines (immersion in molten lead) and I know from working with them that they are very dense and tough - not at all like the chewy resin used in tanks. I imagine the tanks were made in some cottage industry back in the '70s.
I used Caswell on my Fastback tank, and my friends Roadster - I looked into what Caswell is, epoxy phenol novolac resin. It seems to be an industrial sealant - for more info check here. broken link removed
I have no interest in Caswell - just curious as to what the sealeant was - and thinking perhaps we should buy a drum of EPNR and sell it in little cans..... :lol:
Phil

Click to expand...

Thanks for the comments,

As for the circuit board material, I "think" they are all the same, the wave soldering is a quick process and will damage the glue holding the copper clad material to the fiberglass well before it begins to break down. The board came from a module made by DEC in the seventies, I am sure the resin would have been the same as the resin used by Norton at that time. If I ever do another Norton fibeglass tank, I will open it up, sand blast the inside to remove all the gunk old gas leaves in (shellac ??) and refiberglass from the inside with a few more coats of good quality resin and glass cloth and then coat it when it is finished.

Jean

Your response is as meticulous and thorough as your work (as I would expect)!

Any chance of installing a "Jean" in my shop? I could really use one. :wink:

Jeandr said:

The first thing I did was to coat a coke bottle and let it dry completely.

It also looks like a Coke bottle would make a gas tank in a pinch :lol:

Jean

Click to expand...

Ever thought of cross engineering this process to come up with a product that would coat our stomachs to withstand prolonged consumption of coke-a-cola?

There is no way that the circuit board material is the same that the fiberglass tank were made of. The experiment is faulty and results not accurate. Just sayin'.

swooshdave said:

There is no way that the circuit board material is the same that the fiberglass tank were made of. The experiment is faulty and results not accurate. Just sayin'.

Click to expand...

My main concern was that the sealer would not peel away, melt, disolve... in the presence of gasoline or methanol and it didn't so the experiment is valid for those points. If you had see how fast gasoline ate through my Fastback's tank, one week in a bottle is quite enough for me to consider this product safe for my tank.

Jean

Jeandr said:

swooshdave said:

There is no way that the circuit board material is the same that the fiberglass tank were made of. The experiment is faulty and results not accurate. Just sayin'.

Click to expand...

My main concern was that the sealer would not peel away, melt, disolve... in the presence of gasoline or methanol and it didn't so the experiment is valid for those points. If you had see how fast gasoline ate through my Fastback's tank, one week in a bottle is quite enough for me to consider this product safe for my tank.

Jean

Click to expand...

Fair enough. Myth Busted! :mrgreen:

I've read a number of posts on this topic (newbie, here),and am curious in that this MUST be a burning topic of discussion for years now, what with so many 'glass tanks.

Is there any *DEFINITIVE* tank treatment OTHER than going to metal? In all honesty, I'd just as soon keep my father's original Interstate tank, especially as I understand you cannot get them in metal?

Just saying... seems like this would be the major issue a group/forum would have devoted 'major time' to definatively resolving?

I've a definitive (permanent) possible fix in mind, but don't have the expertise experience working with plastics to know the answers. Any of you guys 'plastics people'??

Gary said:

I've read a number of posts on this topic (newbie, here),and am curious in that this MUST be a burning topic of discussion for years now, what with so many 'glass tanks.

Is there any *DEFINITIVE* tank treatment OTHER than going to metal? In all honesty, I'd just as soon keep my father's original Interstate tank, especially as I understand you cannot get them in metal?

Just saying... seems like this would be the major issue a group/forum would have devoted 'major time' to definatively resolving?

I've a definitive (permanent) possible fix in mind, but don't have the expertise experience working with plastics to know the answers. Any of you guys 'plastics people'??

Click to expand...

I'd recommend Caswells. The trick is the correct and proper application. I'd never use anything else.

Gary said:

I'd just as soon keep my father's original Interstate tank, especially as I understand you cannot get them in metal?

Click to expand...

Only the first 750 Interstate tanks were fibreglass. All the later ones were steel. The steel ones also held about half a gallon more.

i used hirsch on the reccommendation of the guy i bought my bike from, a knowledgeable dude. i called hirdch to order the sealer and the owner talked me thru applying it. as w/ most things preparation is key. mine's not leaked after 6 months, i know, not an endurance test bt any means. i run avgas 100 about half the time and pump 91 when i'm out.

Oh! Excellent, I hadn't even realized any were of metal untikl just a few days ago. Well, I'm sort of a 'permanent fix' type of guy (when I can be), though also known to do the temp 'patch' thing. ANYWAY: my thought for (to me) the most obvious 'perm' fix, would be to take a large (or several large) ethanol safe fuel cans... you know, the red plastic ones sold here in the States? Anyway, somehow get them melted hot enough where I could pour, say, a half a gallon into the tank, do a 15-20 second 'rinse' of the tank, coating it with the plastic, then immediately draining it out.

1.) obvious, because those tanks will hold fuel for years without adverse effect (to the plastic, that is).
2.) problem would be... how fast could the excess be removed before it hardened up.
3.) overcoming #2 above... who cared if I had to drill through a half inch of plastic for the fuel valves (or 2.5 cm's, whatever). The point is, ergo, no more worries. Ethanol does NOT attack these fuel drums, and those plastic fuel drums are the only thing I *know of* formulated to not be effected by the ethanol.

Anyway, could be other plastics out there just as good (currently experimenting with empty plastic milk jug filled with fuel).

But you've got to admit that on the surface, the idea of coating the inside of the tank, as per Caswell, POR-15, etc... but with the permanent plastic MADE for that purpose, well, it certainly DOES sound most reasonable, doesn't it? Anyway, I am toying with experiments along this line, and would appreciate ALL of your thoughts.
By the way, if I go with a purchased treatment, it is my GUESS that Caswell is the way to go. Again... thoughts? Caswell?

RGR: I could only wish you'd first done it a decade ago, so you could then tell us it worked perfect, lol's!

well 2019 then gary!

Gary I used Caswell about 4 or 5 months ago, has been sitting for about 3 weeks with a full tank of premium ulp. For the first time the oil has run into the crankcase and I will have to drain some before I fire her up but I just stuck my finger in the tank and the Caswell coating still feels hard. Before I coated the tank it felt tacky and on a run it started to play up and on removal of the carburetures the intakes were coated with a blueish gunk. There is photos on here of someones manifoild that looked the same as mine. I dont know why it happened here as we have not yet gone to ethanol in all fuels, you can still buy ethanol free fuel. May have had the wrong fuel in it before it came to Oz. The only problem I had with the Caswell was I done it in the middle of our winter and it was hard to get it to run all around and tip out the excess, I think it would run better if it was warmer. Our version of winter is not the same as most of the members on this site and we can ride all year round. I would do it on a summer day.
Ian

As I said, I would not be afraid of a fibreglass tank, my café's tank is made of the stuff. One thing is that no gas ever was in my tank so there was no deposit of varnish or other gunk ready to be dissolved by the new fuels. If I had a fiberglass tank to do, I would cut the bottom out, really clean the insides by sandblasting it, the I would add a few coats of fibreglass cloth and resin, close it up really well and coat it with Hirsh tank sealer just as I have done with my present tank. These are the exact steps I made and so far after more than a month with gas in the tank, no evidence of any degradation.

For what it's worth, gas station tanks were swapped from steel tanks which rusted and leaked to fibreglass tanks, granted they use really thick fibreglass, but they don't rust and they don't leak. The main reason to go away from glass tanks was because of their tendency to split and spill fuel in an accident. The gunk we see in our carburettors is probably accumulated garbage let loose by new fuels, not ethanol nor methanol.

Jean

The gunk we see in our carburettors is probably accumulated garbage let loose by new fuels, not ethanol nor methanol.

Click to expand...

I wish this were the case. Early fiberglass tanks were made using polyester resins in the glass mat. Polyester is not resistant to many alcohols and other oxygenated solvents. Theses blends in today's gasoline slowly begins to dissolve the cured polyester resin. Modern tanks are usually made from vinyl ester or epoxy resins which are quite resistant when cured. Lining the tank with a cured epoxy resin should be resistant if done properly. However, I would not trust that just because you buy a new tank it was made with something other than polyester.

The large steel gasoline storage tanks are lined with epoxy coatings to prevent damage from water and rusting. Those tanks are used for many years.

http://buyat.ppg.com/REP_aerospace_files/IndSealants/pr-670_05_08_web.pdf